POJ 2828Buy Tickets

POJ 2828

题目大意是说有n个插入操作，每次把B插入到位置A，原来A以后的全部往后移动1,球最后的序列

tree里保存的应该是这整个区间还有多扫个位置可以插入数据，那么线段树里从后往前扫描依次插入数据

比如现在吧B插入到A位置，如果整个区间左侧还有<A个位置可以插入数据，那么就只能将其放到整个区间的右侧，递归下去就可以了

 1 void update(int k, int L, int R, int x)
 2 {
 3     if(L == R) { pre[k] = r; ans[L] = val; return ; }
 4
 5     int mid = (L+R)>>1;
 6
 7     if(x <= pre[k<<1]) update(lson, x);//左侧的多余x
 8
 9     else update(rson, x-pre[k<<1]);//否则往右
10
11      pre[k] = pre[k<<1] + pre[k<<1|1];
12 }

 1 #include <map>
 2 #include <set>
 3 #include <stack>
 4 #include <queue>
 5 #include <cmath>
 6 #include <ctime>
 7 #include <vector>
 8 #include <cstdio>
 9 #include <cctype>
10 #include <cstring>
11 #include <cstdlib>
12 #include <iostream>
13 #include <algorithm>
14 using namespace std;
15 #define INF 1e9
16 #define inf (-((LL)1<<40))
17 #define lson k<<1, L, mid
18 #define rson k<<1|1, mid+1, R
19 #define mem0(a) memset(a,0,sizeof(a))
20 #define mem1(a) memset(a,-1,sizeof(a))
21 #define mem(a, b) memset(a, b, sizeof(a))
22 #define FOPENIN(IN) freopen(IN, "r", stdin)
23 #define FOPENOUT(OUT) freopen(OUT, "w", stdout)
24 template<class T> T CMP_MIN(T a, T b) { return a < b; }
25 template<class T> T CMP_MAX(T a, T b) { return a > b; }
26 template<class T> T MAX(T a, T b) { return a > b ? a : b; }
27 template<class T> T MIN(T a, T b) { return a < b ? a : b; }
28 template<class T> T GCD(T a, T b) { return b ? GCD(b, a%b) : a; }
29 template<class T> T LCM(T a, T b) { return a / GCD(a,b) * b;    }
30
31 typedef __int64 LL;
32 //typedef long long LL;
33 const int MAXN = 200005;
34 const int MAXM = 100005;
35 const double eps = 1e-10;
36 const LL MOD = 1000000007;
37
38 int N, pre[MAXN<<2];
39 int id[MAXN], num[MAXN], ans[MAXN];
40 int r, val;
41
42 int buildTree(int k, int L, int R)
43 {
44     if(L == R) return pre[k] = 1;
45     int mid = (L+R)>>1;
46     return pre[k] = buildTree(lson) + buildTree(rson);
47 }
48
49 void update(int k, int L, int R, int x)
50 {
51     if(L == R) { pre[k] = r; ans[L] = val; return ; }
52
53     int mid = (L+R)>>1;
54
55     if(x <= pre[k<<1]) update(lson, x);
56
57     else update(rson, x-pre[k<<1]);
58
59      pre[k] = pre[k<<1] + pre[k<<1|1];
60 }
61
62 int main()
63 {
64     while(~scanf("%d", &N))
65     {
66         buildTree(1, 1, N);
67         for(int l=1;l<=N;l++)
68             scanf("%d %d", &id[l], &num[l]);
69         r = 0;
70         for(int i=N;i>0;i--)
71         {
72             val = num[i];
73             update(1, 1, N, id[i] + 1);
74         }
75         for(int i=1;i<=N;i++) printf("%d%c", ans[i], i==N?‘\n‘:‘ ‘);
76     }
77     return 0;
78 }

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